Las Vegas school goes on lockdown after gun threat

With images of the massacre at Virginia Tech fresh in their minds, students and parents at Desert Pines High School in Las Vegas were sent into a panic on Tuesday after an 18-year-old man flashed a handgun on campus. Even though no one was hurt, many assumed the worst when the school was placed on lockdown. Students were kept in their classrooms or taken to the school's gymnasium to wait out the threat.